Power wire and distribution block setup

skiWVUxtm · 03-05-2007, 08:33 PM

Just checking if I'm on the right track for my setup:

From the battery positive terminal I'm running 4 awg wire, with an inline fuse within 18" of the battery, to a fused distribution block in the truck (more like the middle of the vehicle). From the distribution block I'll be running two 8 awg wires, one to my eD NINe.4 amplifier and the other to my PSU though initially I'll only be setting up the amplifier (will add the PC setup later). The amplifier will be powering two front speakers (Infinity Kappa 680.7cs) and a sub (Infinity Reference 850w). I'll be using 12 awg wire to connect both the speakers and sub. Since I won't be setting up the PSU/PC quite yet I'll just hook up the amplifier to my stock headunit for the time being. That should be it for my audio setup...

Couple questions:
1. Do I need to run 4 awg wire from the battery negative terminal to the vehicle's body (along with the grounds from the amplifier and PSU)?
2. Should the ground wire from the amplifier and PSU both be attached to the same grounding point on the vehicle's body or does it really matter? The reason I ask is because the PSU/PC setup will most likely be in my center console (in place of my CD changer).
3. Is it fine to connect both the speakers and sub using the 12 awg wire?

Any other feedback/suggestions would be greatly appreciated =)

Thanks!

- TL

DarquePervert · 03-05-2007, 09:19 PM

1. No.

2. That's a matter of debate. I have a distro block for both power and ground, so all my grounds will be to the same point.

3. I'll let someone else weigh in on this, as I don't know.

lbridges · 03-05-2007, 09:22 PM

Well, I'm a noob on carputers (been lurking for months here and self-teaching Photoshop, Flash, etc), but I've done car audio for many, many years.

Q1: This is one leg of what is/was known as the "big 3". The other being batt+ to alternator, and batt- to engine block. If you do the batt+ to alternator wire, don't overlook fusing (using a fuse or fusible link).

Q2: Becomes an issue only if you find yourself with ground loop problems. However, a rule of thumb is that anything in the audio stream should be connected to a common ground point to help avoid ground loops (and attendant alternator whine).

Q3: 12 gauge is fine for your proposed sub, 12 is overkill for the main speakers, but won't hurt anything (16 would be OK).

skiWVUxtm · 03-05-2007, 10:52 PM

@DarquePervert

Thanks for the info. I was thinking about doing the distro block for my grounding but since the PSU and amplifier aren't near each other I didn't want those wires going long distance (trying to keep them as short as possible).

@lbridges

1. So it sounds like this isn't necessary but it could help with reducing voltage drops and less strain on the vehicle's charging system (via Big 3 thread).

2. Hopefully I won't have the ground loop issues but if that is the case then it sounds like I will have to rethink the location of my amplifier and PSU. I guess if this is the case then I could get the distro block and ground everything in one central location.

3. Ok, I was just wondering. Maybe I'll hold onto the extra 12 awg and get some 16 awg which might be a little easier to feed around the vehicle.

Thanks much!

- TL

RedGTiVR6 · 03-06-2007, 07:32 AM

you actually want smaller gauge wire for your highs and mids.

it has to do with slowing down the electron flow so that your audio signal will not travel quicker to your mids/highs than it will to your subs.

J187 · 03-06-2007, 08:21 AM

All though upgrading the ground strap from neg to chassis IS part of the "Big 3" I'm concerned by your post that you are considering just running a ground wire to the chassis without realizing that you are supposed to be changing the one that already exists, not just adding another. Also, unless its just something you want to do, you may want to verify that you have a ground problem w/ you vehicle before going to all that effort. YOu may not need the big 3 after all.

Ground all of your audio sources that are in the same audio loop to the same location. Other sources that have nothing to do w/ the loop can be grounded in isolation. An example of loop would be radio to amp. Ground the amps with the shortest possible wire OF THE SAME AWG AS YOUR POWER INPUT WIRE TO THAT AMP to the nearest, THICK metal structure. Use a gritty sand paper and sand the metal area if painted or treated with anything, and after connecting the ground wire, spray over it w/ an anti corrosive primer or paint. Using a smaller AWG wire for your interior mains is actually sound advice (sorry, pun intended). 12awg is right for the sub, but even 16 would be fine for your infinity speakers, 14 if you insist, but no bigger.

skiWVUxtm · 03-06-2007, 08:11 PM

Quote: Originally Posted by RedGTiVR6

you actually want smaller gauge wire for your highs and mids.

it has to do with slowing down the electron flow so that your audio signal will not travel quicker to your mids/highs than it will to your subs.

Great, thanks for the info!

Quote: Originally Posted by J187

All though upgrading the ground strap from neg to chassis IS part of the "Big 3" I'm concerned by your post that you are considering just running a ground wire to the chassis without realizing that you are supposed to be changing the one that already exists, not just adding another. Also, unless its just something you want to do, you may want to verify that you have a ground problem w/ you vehicle before going to all that effort. YOu may not need the big 3 after all.

Yes, thank you as I was confused about running an additional wire from the negative terminal to the chassis. If I run into any ground loop problems then I'll revisit this "Big 3" for replacing those wires. Thanks for your help and clarification.